1. Field of the Invention
This invention relates to an auto-lock slider or a free-type slider, for a concealed slide fastener, in which the pull-tab-supporting point of a clamp is low in level so as to touch a cloth during opening the fastener chain or stopping the slider, while the pull-tab-supporting point of the clamp is high in level during closing the fastener chain.
2. Description of the Related Art
In a conventional free-type slider to be used in a concealed slide fastener, a planar triangle-type clamp is pivotally connected at one end to an attachment lug standing on an upper surface of a guide post of the slider body an other end to a pull tab.
Japanese Utility Model Laid-Open Publication No. Hei 7-16608 discloses an auto-lock slider for a concealed slide fastener as shown in FIG. 10 of the accompanying drawings. In this auto-lock slider, a planar triangle-type clamp 3' is loosely threaded at one end on a locking lever 4', which is pivotally mounted on an attachment lug 6' standing on a guide post and is urged by a U-shaped leaf spring 28' in such a manner that a locking pawl 16' of the locking lever 4' normally projects into an element guide channel 8' in the slider body 1', and at the other end or base end to a pull tab 2'.
Further, Japanese Utility Model Publication No. Hei 7-21122 discloses a slider for an ordinary type slide fastener as shown in FIG. 11. In this slider, a clamp 3" for connecting a pull tab to a slider body has a planar circular aperture 19" and has at one end a pivot portion 40, at the outside of which a pull-tab-attaching hook 22" bulges integrally. Further, a U-shaped resilient plate 28", which covers the pivot portion 40, has at one end an outward punched-out tongue 41 to be engaged in an upper recess in the upper inner surface of the hook 22" and at the other end an outwardly bent portion 42 resiliently touching a lower recess 26" of an end portion of the hook 22". The aperture 19" of the clamp 3" is threaded on an attachment lug standing on the slider body.
In either of the above-mentioned convention free-type slider or the auto-lock slider of FIG. 10, since the clamp will stand up to project from a cloth such as a garment due to the pressure of an edge portion of the cloth when the slider is stopped, a pull-tab-attaching point of the clamp will be raised high so that the pull tab can swing freely during using, which makes the slider unsightly. In the conventional auto-lock slider, since the clamp 3' is not directed in one way and will fall in opposite sideways freely if the pull tab 2' is gripped in a certain way when the clamp 3' pulls up the locking lever 4' during closing the fastener chain, frictional resistance on the cloth is inevitably large so that smooth movement of the slider cannot be realized particularly if the cloth is thick.
In the clamp 3" of FIG. 11, which is to be used in the ordinary type slide fastener, the aperture 19" of the clamp 3" has a large circular shape so that frictional resistance on the cloth is so large to damage the cloth during closing and opening the fastener chain. Therefore this clamp 3" cannot be used for an concealed slide fastener. Further, since the resilient plate 28" extending astride of the pivot portion 40 of the clamp 3" is not fixed to the clamp 3", it tends to jog within the clamp 3" so that smooth pulling of the pull tab is difficult to achieve.